Mediastinitis

Mediastinitis is a severe, life-threatening infection of the mediastinal space, most commonly occurring after median sternotomy for cardiac surgery (1-3% of cases) or from esophageal perforation (Boerhaave syndrome, instrumentation). Post-sternotomy mediastinitis typically develops 7-14 days postoperatively when bacteria (Staphylococcus aureus, coagulase-negative staphylococci, gram-negative organisms) contaminate the operative field and colonize the sternal wound, spreading to the mediastinal tissues. The infection causes purulent inflammation of the mediastinal connective tissue, pericardium, and great vessels, with risk of sternal dehiscence, septic pericarditis, mycotic aneurysm of the aortic suture line, and overwhelming sepsis. Clinical presentation includes fever, sternal wound drainage, sternal instability (clicking or movement with palpation), leukocytosis, and widened mediastinum on chest radiograph. The nurse assesses the sternal wound for erythema, drainage, and instability at each assessment, monitors for signs of sepsis, administers prolonged IV antibiotic therapy (6-8 weeks), assists with wound care including negative-pressure wound therapy (VAC), monitors for cardiac tamponade symptoms, provides nutritional support to promote wound healing, and educates patients about sternal precautions and wound care following surgical debridement.